Calgary Jeep Association
4x4 Related Groups => Tech Talk => Topic started by: Jeepster on November 26, 2008, 09:43:26 AM
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Long story short I purchased a cheap YJ for winter...
It is blowing black soot from the exhaust and what seems to be water ?
Is it just running rich ?
My plan is to change the Plugs , Wires, Cap, Do Oil change (change oil filter) exchange Rad cause its very worn and add new coolant.
This was a farm vehicle and may not have had a tune up in some time.
Any thoughts on the soot and water ?
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did you put the fuel in the tank?
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No...
As far as I know it has Farm Gas (Purple Gas) in it.
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which engine does it have. if its the 4.2L with the carb then thats probably why it runs like poo. look into swapping that carb out for something a little more reliable.
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Yeah its the 4.2l with the carb...
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Sounds like unburnt gas and not water, spewing out the back, burn off the old purple gas and do your plugs/wires/ect as planned, that should at least make it better, if you still have problems start looking for bad sensors.
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There's a plethora of vacuum operated gadgetry on pre 91 YJ's , all of it disapeared when the HO was introduced.
80's emissions equipment was far more complicated than necessary , was hard to diagnose and understand , pretty much BS to repair and get running properly. Diagnostic tools are non existant , as in code readers and data monitoring tools , adding to the frustration.
Here's some reading ........................
http://home.sprynet.com/~dale02/list.htm
Start there , if you can understand that it will help to locate problems.
It's common to see bypassed microprocessors and re-worked vacuum systems on those old YJ / CJ 's , thank god they only used feedback carbs for a short time.
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Some water from the tailpipe is the result of normal combustion. Look up " nutter bypass" on google and do that. You can eliminate the computer and all the emissions vacuum crap. I've done this to my 89 yj and my 85 cj . Makes a world of difference runningwise and I'm still using the stock carb.
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True , the water in the tail pipe comment , there is a great deal of moisture in the atmosphere , for every ten gallons of fuel burned a gallon of water is produced. Much of this water is discharged quickly as the exhaust gases flow through the tubing , some collects and is seen as drips out the tail pipe. Exhaust systems have a relatively short life span compared to the rest of the car due to this.
My 88 had the whizzy 4.2 / Carter feedback carb setup on it , yup , I bypassed it and used a rebuilt 81 CJ carb for a while. Yes I removed all of the pulse air rubbish , re-configured the vacuum hoses n' stuff , retaining the tac-vac hot air ducting for cold start / warm up. It ran better afterwards but was a pain to do cleanly , perhaps I went overboard , removing the entire underhood wiring harness , surgically removing all traces of the 80's emissions stuff , then re-bundling the harness neatly so an un trained eye couldnt tell. It's not easy to do , there are many splices , runs of resistance wire , relays and various gadgets to confuse the unwary. A wiring diagram and above average understanding of electrical systems is recomended before attempting to do what I did. Would I want to do it again ? , nope , as old school as I am , efi is MUCH easier to work with and runs so much better.
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could be just the gas
purple farm gas (leaded)
you don't know if they accidentally mixed some farm diesel in it too?
I would try and drain all the fuel out and put some proper fuel in it.
Even a litre of diesel mixed with 10 litres of gas will make it run like crap.
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My 89 Yj 4.2 had the same trouble. I threw out the carter carb and put on a rebuilt MC 2100, did the bypass and ran a manual choke. Runs like a charm now.